JPH0524059A - Manufacture of fiber-reinforced thermoplastic resin decorative molded sheet - Google Patents

Abstract

PURPOSE:To obtain the above fiber-reinforced thermoplastic resin molded sheet having a favorable appearance at a low cost, by a method wherein a fiber- reinforced nonpolyolefin thermoplastic resin sheet material is molded by in-mold coating by setting the mold temperature at 130-150 deg.C and the surface of the sheet material is coated with a coating. CONSTITUTION:A fiber-reinforced nonpolyolefin thermoplastic resin sheet material 1 is molded by in-mold coating at a mold temperature of 130-150 deg.C. Then a coating film 2 is formed on the surface of the sheet material 1 and a fiber- reinforced thermoplastic resin decorative molded sheet is manufactured. With this construction, a fiber-reinforced thermoplastic resin molded sheet having a favorable appearance can be obtained at a low cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber-reinforced thermoplastic resin-decorated molded plate, and more specifically, a fiber-reinforced thermoplastic resin sheet material having a poor appearance, a so-called stampable sheet, is coated with a coating film. The present invention relates to a method for forming a decorative molded plate having a good appearance.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
The fiber reinforced thermoplastic resin sheet material is called a stampable sheet (it may be called GMT (glass mat thermoplastic) in the case of glass fiber reinforced),
As a material for forming a stampable sheet, the material is heated and softened, and then press-formed to obtain a fiber-reinforced thermoplastic resin molded plate (stampable sheet molded product).

Since long fibers can be used as a reinforcing agent in this stampable sheet, it is excellent in impact resistance, strength, creep resistance and fatigue resistance, but on the surface of the molded product fiber patterns (fiber patterns) and pinholes are formed. Also, after the raw sheet charged into the mold at the time of molding is seen (charge mark, cold mark), the appearance is not so good, and most of the colors are black, which makes it difficult to color.

For this reason, stampable sheet molded products are used in places such as bumper beams, battery trays, oil pans, fuel tanks, and seat shells that are almost invisible to the naked eye, but by utilizing the excellent characteristics of stampable sheets. In order to expand the application range, it is desired to improve the appearance.

In this case, it is possible to coat the surface of the molded product, but in order to improve the appearance, a putty-filling base treatment and a primer are required, which complicates the coating process and increases the cost. Further, in order to eliminate the fiber pattern and improve the appearance, a method of using a mold with a grain pattern may be considered, but in this case, a deep grain pattern with a concavo-convex portion of 0.5 mm or more is processed on the mold. Therefore, there is a problem that the manufacturing cost of the mold is increased.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a method for easily and efficiently producing a fiber-reinforced thermoplastic resin-decorated molded plate that is inexpensive and has a good appearance.

[0007]

Means and Actions for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventor has conducted a fiber-reinforced non-polyolefin thermoplastic resin sheet material with a mold temperature of 130 to 150 ° C. It has been found that the above object can be achieved by molding by mold coating and forming a coating film on the surface of the sheet material.

That is, the in-mold coating is SM
When molding C (sheet molding compound), S
Once the MC is almost cured, once the mold is 0.2-1 mm
After opening, press-in the paint and paint the SMC surface,
It is known as a method of closing the mold again to cure the coating film and, at the same time, completing the curing of the SMC. This method is a method to obtain a coated article with a good appearance at the same time as molding with good productivity, but this in-mold coating method is
Conventionally, it has been used for a thermosetting resin (FRP), and its application example to a stampable sheet has not been known.

The inventor of the present invention tried to coat a stampable sheet with a polyolefin resin such as polypropylene as a matrix by the in-mold coating method, and found that the coating film swelled and a satisfactory molded product could not be obtained. I found out. The cause of this swelling is that preheating is necessary to soften the matrix resin before forming the stampable sheet by the in-mold coating method, and polypropylene requires about 200 to 230 ° C. or more. It was found that decomposed gas was generated at the time, which caused blistering. On the other hand, when using a non-polyolefin high-performance resin such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, or polyamide as the matrix resin, it was found that blistering can be prevented, and the mold temperature was examined. In order to mold such high-performance resin, if the mold temperature is lower than 130 ° C, the molded product shrinks greatly and the paint leaks from the clearance of the mold cavity, while the mold temperature is higher than 150 ° C. There is no space for the paint to enter, and the paint does not enter at all especially in the vertical portion. Therefore, in the in-mold coating method for the stampable sheet, the mold temperature is set to 1
It was important to control the temperature to 30 to 150 ° C., and it was found that a good coating having excellent adhesion can be obtained, and a method for forming a coating film on a stampable sheet by the in-mold coating method was established.

Therefore, according to the present invention, a fiber-reinforced non-polyolefin thermoplastic resin sheet material is used at a mold temperature of 130 to 1.
Molded by in-mold coating at 50 ℃,
Provided is a method for producing a fiber-reinforced thermoplastic resin decorative molded plate, which comprises forming a coating film on the surface of the sheet material.

The present invention will be described in more detail below. In the present invention, as described above, the fiber-reinforced non-polyolefin thermoplastic resin sheet material is molded by in-mold coating, and a coating film is formed on the surface of the sheet material. It is a thing.

When a polyolefin resin such as polyethylene or polypropylene is used, the coating film swells, resulting in poor appearance and poor adhesion. Therefore, the resin usable in the present invention is a non-olefin thermoplastic resin. resin,
Examples thereof include polycarbonate, polyethylene terephthalate, polyesters such as polybutylene terephthalate, polyamides such as nylon 66, polyacetal, polyphenylene sulfide, polyphenylene oxide, modified polyphenylene oxide, polysulfone, and the like, and one kind thereof may be used alone or two or more kinds may be mixed. Can be used.

Examples of the reinforcing fibers to be mixed with these resins include carbon fibers, metal fibers and glass fibers, the length of which is 3 to 100 mm, particularly 12 to 50.
mm is preferably used, and the mixing ratio thereof is preferably 20 to 50% by weight of the whole sheet material.

In the present invention, the fiber-reinforced non-polyolefin thermoplastic resin sheet material is preheated, charged into a mold and then cooled and solidified for a predetermined time, and then the coating material is mixed with the mold and the sheet material. It is possible to preferably employ a method of injecting in the meantime and then pressurizing and heating for a predetermined time to cure the coating material.

In this case, the preheating method, time and the like can be the same as those for a normal stampable sheet. When this preheated sheet is put into a mold, two or more sheets can be stacked and laminated if necessary.

The temperature of the mold is 13 as described above.
The temperature is set to 0 to 150 ° C., whereby a good coating film having excellent adhesion can be obtained. Put the preheated sheet material into the mold in this temperature range, generally 100-200k
It is cooled and solidified at a mold clamping pressure of g / cm ² for 1 to 3 minutes.

Next, the pressurization of the mold is stopped, and the paint is injected between the mold and the molded sheet material. Either Japanese Laid-Open Patent Publication No. 61-4304) or a method of injecting with the mold closed (Japanese Patent Application No. 1-287217) may be used.

The type of paint is not limited as long as it is an in-mold paint, but a one-part thermosetting type is preferable, and acrylic modified urethane type, epoxy type, unsaturated polyester type and the like are preferable.

The thickness of the coating film is preferably 30 to 300 μm, particularly 40 to 200 μm. If the coating film is thinner than 30 μm, the appearance may be poor, while if it is thicker than 300 μm, the cost may be increased and the molding cycle may be lengthened.

After the paint is injected, the mold clamping pressure is generally 50 to 1
By heating at 50 to 50 ° C./cm ² for 5 to 1 minute at a temperature of 130 to 150 ° C., the coating material is cured to obtain a molded article having a coating film formed on the surface.

A concrete example of the decorative molded plate of the present invention is shown in the drawing. As shown in FIG.
2 may be formed, and as shown in FIG. 2, an intermediate layer 3 such as a wire mesh.
The coating film 2 may be formed on the surface integrated with the sheet material 1 (a wire mesh or the like is laid in advance on the mold before the sheet material is charged).

According to the present invention, it is possible to provide a molded plate having a fast cycle, excellent strength, and excellent appearance. Therefore, the decorative molded plate produced by the method of the present invention is, for example, an exterior material for automobiles and motorcycles, an interior material for automobiles and houses,
It can be suitably used for applications such as housing materials for furniture and home electric appliances, panels for aquariums, parabona antennas, and the like that can be seen by people who have not been able to use the fiber-reinforced thermoplastic resin molded plate.

[0023]

EXAMPLES Hereinafter, the present invention will be specifically shown by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Embodiment] A parabona antenna (35) is formed by using a two-chamfered parabona antenna die 4 shown in FIG.
Shape) was formed and a coating film was formed on the surface.

Sheet 5 (trade name Azloy) reinforced with 35% by weight of glass fiber was placed on a wire mesh in a matrix in which polycarbonate (PC) and polybutylene terephthalate (PBT) were mixed in a ratio of 1: 1 and placed in an oven at 300 ° C. It was heated at about 10 minutes. Take this out quickly,
After stacking two sheets, they were solidified by cooling at a mold clamping pressure of 150 kg / cm ² and a mold temperature of 140 ° C. for about 1 minute. Next, open the mold slightly, inject about 100 g of paint (trade name Prominate IM, one-component thermosetting type epoxy-based paint) from the injector in the center of the mold, and mold clamping pressure of 100 kg / cm.
Heat cured at ² for 2 minutes.

The thickness of the coating film 6 of the obtained molded product is 150 μm.
m, the appearance was excellent, there was no blister, and the molded product was good.

Comparative Example A stampable sheet (Azdel, X sheet) in which long glass fibers and polypropylene were combined was placed on a wire mesh and heated in an oven at 220 ° C. for about 8 minutes. This was put into a mold having the same antenna as that of the example, and was cooled and solidified at a mold clamping pressure of 100 kg / cm ² and a mold temperature of 120 ° C. for about 3 minutes. Then, about 100 g of the same paint as in the example was injected from the injector in the center of the mold, repressurized, and heat-cured at a mold clamping pressure of 100 kg / cm ² for about 10 minutes.

A large number of blisters were generated on the coating surface of the obtained molded product, and the adhesion was not good.

[0029]

According to the method for producing a fiber-reinforced thermoplastic resin decorative molded plate of the present invention, it is possible to obtain a fiber-reinforced thermoplastic resin molded plate having a good appearance at low cost.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a molded plate obtained by the method of the present invention.

FIG. 2 is a cross-sectional view showing another example of a molded plate obtained by the method of the present invention.

FIG. 3 is a cross-sectional view of a parabona antenna mold used in the examples.

[Explanation of symbols]

 1 Fiber-reinforced thermoplastic resin sheet material 2 Coating film 4 Parabona antenna mold

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Claims (1)

Claim: What is claimed is: 1. Forming a fiber-reinforced non-polyolefin thermoplastic resin sheet material by in-mold coating at a mold temperature of 130 to 150 ° C. to form a coating film on the surface of the sheet material. A method for producing a fiber-reinforced thermoplastic resin-decorated molded plate, which is characterized.